Re: [RFC 02/18] remoteproc: Introduce virtio device add/remove functions in core.

From: Arnaud POULIQUEN
Date: Wed Apr 22 2020 - 08:30:59 EST


Hi Mathieu

On 4/21/20 10:41 PM, Mathieu Poirier wrote:
> Hey Arnaud,
>
> I have started to review this set. Comments will come in over the next few days
> and I will be sure to let you know when I'm done.

Take as much time you need, there is already a lot in your pipe.
This RFC could be probably split into a few series, but i preferred to keep all
together to have a whole picture. Aim of this RFC is to open the discussion on
the restructuring of the rproc_virtio and the use of components to synchronize child devices.

Thanks!

Arnaud

>
> On Thu, Apr 16, 2020 at 06:13:15PM +0200, Arnaud Pouliquen wrote:
>> In preparation of the migration of the management of rvdev in
>> rproc_virtio, this patch spins off new functions to manage the
>> virtio device.
>>
>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>
>> ---
>> drivers/remoteproc/remoteproc_core.c | 149 +++++++++++++++------------
>> 1 file changed, 83 insertions(+), 66 deletions(-)
>>
>> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
>> index 2a0425ab82a7..5c90d569c0f7 100644
>> --- a/drivers/remoteproc/remoteproc_core.c
>> +++ b/drivers/remoteproc/remoteproc_core.c
>> @@ -441,6 +441,86 @@ static void rproc_rvdev_release(struct device *dev)
>> kfree(rvdev);
>> }
>>
>> +static int rproc_rvdev_add_device(struct rproc_vdev *rvdev)
>> +{
>> + struct rproc *rproc = rvdev->rproc;
>> + struct fw_rsc_vdev *rsc = rvdev->rsc;
>> + char name[16];
>> + int ret, i;
>> +
>> + /* Initialise vdev subdevice */
>> + snprintf(name, sizeof(name), "vdev%dbuffer", rvdev->index);
>> + rvdev->dev.parent = &rproc->dev;
>> + rvdev->dev.dma_pfn_offset = rproc->dev.parent->dma_pfn_offset;
>> + rvdev->dev.release = rproc_rvdev_release;
>> + dev_set_name(&rvdev->dev, "%s#%s", dev_name(rvdev->dev.parent), name);
>> + dev_set_drvdata(&rvdev->dev, rvdev);
>> +
>> + ret = device_register(&rvdev->dev);
>> + if (ret) {
>> + put_device(&rvdev->dev);
>> + return ret;
>> + }
>> + /* Make device dma capable by inheriting from parent's capabilities */
>> + set_dma_ops(&rvdev->dev, get_dma_ops(rproc->dev.parent));
>> +
>> + ret = dma_coerce_mask_and_coherent(&rvdev->dev,
>> + dma_get_mask(rproc->dev.parent));
>> + if (ret) {
>> + dev_warn(&rvdev->dev,
>> + "Failed to set DMA mask %llx. Trying to continue... %x\n",
>> + dma_get_mask(rproc->dev.parent), ret);
>> + }
>> +
>> + /* parse the vrings */
>> + for (i = 0; i < rsc->num_of_vrings; i++) {
>> + ret = rproc_parse_vring(rvdev, rsc, i);
>> + if (ret)
>> + goto free_rvdev;
>> + }
>> +
>> + /* allocate the vring resources */
>> + for (i = 0; i < rsc->num_of_vrings; i++) {
>> + ret = rproc_alloc_vring(rvdev, i);
>> + if (ret)
>> + goto free_vg;
>
> I don't get the "free_vg" part... At the moment this patch is only about
> refactoring and as such I would encourage you to keep things the same as
> much as possible. It is certainly ok to make modifications but they should be
> done in an incremental patch. Otherwise reviewers needlessly have to scrutinize
> the changes thinking there is something more to figure out.
>
>> + }
>> +
>> + rvdev->subdev.start = rproc_vdev_do_start;
>> + rvdev->subdev.stop = rproc_vdev_do_stop;
>> +
>> + rproc_add_subdev(rproc, &rvdev->subdev);
>> +
>> + return 0;
>> +
>> +free_vg:
>> + for (i--; i >= 0; i--) {
>> + struct rproc_vring *rvring = &rvdev->vring[i];
>> +
>> + rproc_free_vring(rvring);
>> + }
>> +
>> +free_rvdev:
>> + device_unregister(&rvdev->dev);
>> +
>> + return ret;
>> +}
>> +
>> +static void rproc_rvdev_remove_device(struct rproc_vdev *rvdev)
>> +{
>> + struct rproc *rproc = rvdev->rproc;
>> + struct rproc_vring *rvring;
>> + int id;
>> +
>> + for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
>> + rvring = &rvdev->vring[id];
>> + rproc_free_vring(rvring);
>> + }
>> +
>> + rproc_remove_subdev(rproc, &rvdev->subdev);
>> + device_unregister(&rvdev->dev);
>> +}
>> +
>> /**
>> * rproc_handle_vdev() - handle a vdev fw resource
>> * @rproc: the remote processor
>> @@ -473,8 +553,6 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
>> {
>> struct device *dev = &rproc->dev;
>> struct rproc_vdev *rvdev;
>> - int i, ret;
>> - char name[16];
>>
>> /* make sure resource isn't truncated */
>> if (struct_size(rsc, vring, rsc->num_of_vrings) + rsc->config_len >
>> @@ -505,83 +583,22 @@ static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc,
>> kref_init(&rvdev->refcount);
>>
>> rvdev->rsc = rsc;
>> + rvdev->rsc_offset = offset;
>> rvdev->id = rsc->id;
>> rvdev->rproc = rproc;
>> rvdev->index = rproc->nb_vdev++;
>>
>> - /* Initialise vdev subdevice */
>> - snprintf(name, sizeof(name), "vdev%dbuffer", rvdev->index);
>> - rvdev->dev.parent = rproc->dev.parent;
>> - rvdev->dev.dma_pfn_offset = rproc->dev.parent->dma_pfn_offset;
>> - rvdev->dev.release = rproc_rvdev_release;
>> - dev_set_name(&rvdev->dev, "%s#%s", dev_name(rvdev->dev.parent), name);
>> - dev_set_drvdata(&rvdev->dev, rvdev);
>> -
>> - ret = device_register(&rvdev->dev);
>> - if (ret) {
>> - put_device(&rvdev->dev);
>> - return ret;
>> - }
>> - /* Make device dma capable by inheriting from parent's capabilities */
>> - set_dma_ops(&rvdev->dev, get_dma_ops(rproc->dev.parent));
>> -
>> - ret = dma_coerce_mask_and_coherent(&rvdev->dev,
>> - dma_get_mask(rproc->dev.parent));
>> - if (ret) {
>> - dev_warn(dev,
>> - "Failed to set DMA mask %llx. Trying to continue... %x\n",
>> - dma_get_mask(rproc->dev.parent), ret);
>> - }
>> -
>> - /* parse the vrings */
>> - for (i = 0; i < rsc->num_of_vrings; i++) {
>> - ret = rproc_parse_vring(rvdev, rsc, i);
>> - if (ret)
>> - goto free_rvdev;
>> - }
>> -
>> - /* remember the resource offset*/
>> - rvdev->rsc_offset = offset;
>> -
>> - /* allocate the vring resources */
>> - for (i = 0; i < rsc->num_of_vrings; i++) {
>> - ret = rproc_alloc_vring(rvdev, i);
>> - if (ret)
>> - goto unwind_vring_allocations;
>> - }
>> -
>> list_add_tail(&rvdev->node, &rproc->rvdevs);
>>
>> - rvdev->subdev.start = rproc_vdev_do_start;
>> - rvdev->subdev.stop = rproc_vdev_do_stop;
>> -
>> - rproc_add_subdev(rproc, &rvdev->subdev);
>> -
>> - return 0;
>> -
>> -unwind_vring_allocations:
>> - for (i--; i >= 0; i--)
>> - rproc_free_vring(&rvdev->vring[i]);
>> -free_rvdev:
>> - device_unregister(&rvdev->dev);
>> - return ret;
>> + return rproc_rvdev_add_device(rvdev);
>> }
>>
>> void rproc_vdev_release(struct kref *ref)
>> {
>> struct rproc_vdev *rvdev = container_of(ref, struct rproc_vdev, refcount);
>> - struct rproc_vring *rvring;
>> - struct rproc *rproc = rvdev->rproc;
>> - int id;
>> -
>> - for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
>> - rvring = &rvdev->vring[id];
>> - rproc_free_vring(rvring);
>> - }
>>
>> - rproc_remove_subdev(rproc, &rvdev->subdev);
>> + rproc_rvdev_remove_device(rvdev);
>
> At this time I don't see how introducing rproc_rvdev_remore_device() is
> advantageous. Maybe I'll find an answer as I review upcoming patches...
>
> Thanks,
> Mathieu
>
>> list_del(&rvdev->node);
>> - device_unregister(&rvdev->dev);
>> }
>>
>> /**
>> --
>> 2.17.1
>>